The present invention relates to a control method and apparatus, and more particularly, to a wireless control method and apparatus, which are used, for example, in controlling HVAC equipment, controlling the flow of fluids or gases, controlling rates of different objects, controlling pressure, controlling temperature, or the like.
In temperature comfort control, older systems utilize a passive non-powered thermostat that usually includes a bi-metal element or coil. The thermostat senses the temperature within a space, and that co-acts with an electrical contact coupled to a two-wire control line that commands the heating or cooling function of a particular comfort conditioner. A manual actuator is provided for setting the desired temperature to be maintained. The control operates because changes in the length of the bi-metal element will cause the contact to either separate or electrically connect the wires comprising the control line. This energizes or disables the controller that operates the heating or cooling system.
The use of baseboard electric heat that is equipped with an integral bi-metal thermostat control, and portable air conditioners, are prevalent in vintage construction. For example, in subsidized multi-family housing where the initial cost was of primary concern, bi-metal thermostats are used. Also, inefficient portable air conditioners are placed in windows or walls. These controls are imprecise and are typically located at the point of heating or cooling. Furthermore, they are difficult to regulate and a nuisance to adjust. Consequently, their thermostats are set and left in a relatively high demand for heating or cooling. It is common for occupants to open windows for controlling comfort level where electric baseboard heating is used.
There are several disadvantages to comfort control systems using mechanical thermostats. For example, despite the use of anticipator devices, such thermostats have uncomfortable deadbands. The placement of the thermostats, if not in the heater or air conditioning (AC) unit, is based on the inconvenience of the permanent wiring rather than on the location to be controlled. Furthermore, there is no provision for automatic setback for comfort or energy saving.
Previous studies by the Electric Power Research Institute, and others, have shown that as much as 30% savings can be obtained through full-featured precision programmable line-voltage thermostats instead of using bi-metal controls. However, retrofitting to wall mounted line-voltage thermostats requires hard-wired connections to each baseboard heating element or portable air conditioner. To accomplish this, significant renovations are required to install new wiring, or wire molding must be surface-mounted along floorboards, around doorways, and around windows to enclose the wire. Also, the new thermostats typically need to be located at the farthest location away from the electric baseboard and air conditioner for the control to properly regulate the room temperature. Consequently, retrofitting typically is not considered.
In newer temperature control systems, digital circuitry and/or microprocessor integrated circuits (ICs) allow thermostats, requiring electrical power for their operation, to provide computational and control functions. Furthermore, some digital thermostats permit user-programming, allowing, for example, temperature set-back when a cooler or warmer temperature can be maintained instead of one temperature. However, the cost of retrofitting existing buildings is expensive and generally retrofitting is not considered.
The use of wireless control of a portable air conditioner or portable electric space heater also includes a portable thermostat combined with a control signal transmitter that is placed on a table, desk or stand. This maintains a uniform level of air temperature comfort in the portion of the room where the thermostat is located. A wireless control receiver that is responsive to the transmitted control signal is included as a portion of a plug-in-adapter module and plugs directly into a power wall receptacle. An ordinary window air conditioner or portable space heater is then plugged into the adapter module providing on and off control. However, this embodiment uses a temperature anticipator method of control and does not efficiently control temperature where used and is only local-zone-ambient-temperature responsive. This system anticipates shutting down in the event of absence of wireless control signals. However, shutting down could cause complete and potentially harmful loss of space temperature control resulting in freezing pipes, or an unsuitable temperature environment. Furthermore, the components of this system can be misplaced or stolen because they are not permanently attached. It is not intended to retrofit hard-wired electric baseboard heaters or air conditioners but only plug-and-cord connected equipment. Finally, the thermostat is intended for connection to only one comfort conditioner at a time and will not automatically operate both heating and cooling loads as required.
New applications and growth of data networking have created unforeseen demands and opportunities for temperature control apparatus and methodology. The need for real-time information is critical to the efficient operation of many industries. For example, the utility industries, because of deregulation and increased competition, demands increased efficiencies in the utility systems. These increased efficiencies require better information and control and heightens the need for near real-time monitoring. One such solution uses a wide-area remote telemetry system which monitors and controls remote devices by means of an information control system. The system uses a sensor interface module that constantly monitor devices for triggering events. The sensor interface modules transmit information to at least one data collection modules that gathers, processes, stores and transmits information via external communications. The host module receives, records, processes, and transmits information to the network. The information may then be transmitted to the user as desired. However, this system does not respond to changes and automatically make those changes to efficiently operate a process. User intervention is required to make adjustments to the process to have it operate in response to those changes.
What is needed is a control apparatus that is permanently affixed to its location and does not require an expensive retrofit because of hard wiring. What is further needed is a control apparatus that controls by proportional integral differential measuring elapse of time for real-time control to increase efficiency of systems. Also, what is needed is a control apparatus that provides precision control from a single sensor to many devices providing efficient equipment control. Finally, what is needed is an innovative control solution to effectively address the needs of energy conservation and demand control, specifically, performance contracting retrofit temperature control opportunities, and temperature or duty cycle based load curtailment.
One aspect of the claimed invention is to control by a proportional integral differential, measuring elapse of time for real-time control, to increase accuracy and efficiency of systems.
Another aspect of the claimed invention is to permanently affix it to its location so that hard-wired retrofits are not required.
It is another aspect of the claimed invention to provide precision control of unrelated comfort conditioning equipment such as window air conditioners and electric heat.
It is still another aspect of the claimed invention to provide a gateway interface to external data networks for various purposes including demand control.
It is yet another aspect of the claimed invention to provide control through inclusion of an intelligent processing control algorithm, and two-way wireless communication for passing parametric data between the sensor and actuator device.
It is still another aspect of the claimed invention to provide third-party supervisory control and monitoring through a wireless microprocessor system allowing building-area-network capability through a store-and-forward repeater protocol.
It is yet still another aspect of the claimed invention to ensure several independent installations co-located in a small area that do not mutually interfere due to their common wireless communication channel.
A control apparatus includes a power supply for providing appropriate current and voltage to modules of the control apparatus. A user interface microprocessor module provides the necessary architecture to process user inputs as well as programmable control logic. Furthermore, there is a communications microprocessor module initiating data traffic signals among all control apparatus modules through a wireless transceiver module. Finally, a remote control node module, through a transceiver, interprets and acts upon wireless traffic signals to control an operation.
A method of operating a control apparatus includes the user operating the apparatus by energizing a power supply for providing appropriate current and voltage to modules of the control apparatus. The user interacts with a user interface microprocessor module that provides the necessary architecture to handle user inputs as well as programmable control logic. The user interface microprocessors begin commanding a communications microprocessor module that provides data traffic signals among the control apparatus modules. Two or more transceivers, one at the remote control node(s), exchange wireless data traffic signals to control an operation.
These and other aspects of the claimed invention will become apparent from the following description, the description being used to illustrate a preferred embodiment of the claimed invention when read in conjunction with the accompanying drawings.